Have your opening repertoire built for you
Pick the position to start from and the engine fills in the rest, your moves chosen for you, the opponent’s replies covered to a target depth. It runs in the background and takes a few minutes. Then open it, change what you disagree with, and review it a few minutes a day - the trainer decides which positions are due. Name a Lichess or chess.com player and the tree follows their moves wherever their games cover the line.
How it builds the tree
- The engine does the work: Choose a starting position and the whole tree gets filled in: your moves picked by the engine, the opponent's replies covered to a target. It runs in the background, so you can close the page and come back to it.
- It stops rather than guessing: Where no reply holds the evaluation floor, or the book runs out of games, the run leaves that line unfinished and says which it was. What you get back is a tree that stands up, plus a short list of the decisions that are genuinely yours.
- Then review what is due, not the whole tree: Every position carries its own due date: answer it right and it comes back later, get it wrong and it is back tomorrow. A session is whatever has come due, usually a few minutes, instead of the whole repertoire every time. On a miss you get the engine’s verdict on what you played beside your own move, and the position comes round again before the session ends.
- Build it the way a player you admire plays it: Name a Lichess or chess.com player and the run fetches their games. Wherever they have played a position often enough, the repertoire makes their move; where their games run out, the engine and the book take over. Their moves are still held to your evaluation floor, and the run lists every position where it refused one.
Where to go next
- Practice an opening: Play an opening against responses taken from real games at the rating level you choose.
- Middlegame training: Study the plans in the positions your repertoire leads to.
Questions players ask
How much of the repertoire does it actually build?
The whole tree from the position you choose, your moves selected by the engine, the opponent’s replies covered to a target depth. It runs in the background and takes several minutes; you can leave the page. Each run creates its own repertoire, so trying different settings means generating into a fresh one. Once it exists you do not have to drill all of it: the trainer introduces new positions gradually and brings each one back as it falls due.
Do I need to pay to generate one?
No. A free account generates one repertoire every 7 days. Tier 1 raises that to one every 24 hours. You do need an account - generation is not available to guests, because a run has to be counted against something.
Can I still build or import a repertoire by hand?
Yes, and the generated tree opens in the same builder. Every candidate move shows its share of games, win/draw/loss split and average rating from our opening database alongside the engine's top three. A position reached by two move orders is stored once, and you can import a PGN to merge lines in or export the tree back out.
How often do I have to review it?
A few minutes on the days you turn up. The trainer schedules each position separately, so a session is whatever has come due rather than the whole repertoire - moves you keep getting right stretch out to weeks or months, and the ones you keep missing come back the next day. Skipping days is fine: the schedule works from when you actually show up, not from when it hoped you would, so nothing piles up as a penalty. New positions are introduced a few at a time so that tomorrow stays small.
Can it copy a specific player’s repertoire?
Yes. Give it a Lichess or chess.com username (say, the player whose Stafford Gambit you keep losing to) and start the repertoire at that opening’s position, so the evaluation floor measures against the gambit rather than against move one. The run fetches their recent blitz, rapid and classical games while it works, then deletes them again when it finishes. Where they have played a position at least three times, the repertoire plays their most common move; elsewhere it is built as usual. A move of theirs the engine rejects is not played, and the report says where that happened.